﻿406 
  W. 
  F. 
  FISKE. 
  

  

  It 
  is 
  one 
  of 
  the 
  most 
  important 
  traits 
  of 
  Glossina 
  to 
  be, 
  perhaps, 
  the 
  quickest 
  

   of 
  all 
  biting 
  flies 
  to 
  detect 
  and 
  evade 
  retaliatory 
  movements 
  on 
  the 
  part 
  of 
  its 
  hosts. 
  

   There 
  is 
  no 
  large 
  biting 
  fly 
  known 
  to 
  me 
  which 
  does 
  not 
  possess 
  this 
  self 
  -protecting 
  

   trait 
  ; 
  otherwise 
  stated, 
  there 
  is 
  no 
  large 
  biting 
  fly 
  the 
  behaviour 
  of 
  which 
  I 
  have 
  

   observed 
  that 
  will 
  habitually 
  press 
  its 
  attack 
  upon 
  an 
  aroused 
  and 
  unwilling 
  host 
  

   regardless 
  of 
  consequences 
  to 
  itself. 
  Recently 
  I 
  have 
  been 
  studying 
  the 
  behaviour 
  

   of 
  Tabanids 
  of 
  various 
  species 
  toward 
  animals 
  of 
  many 
  kinds 
  in 
  the 
  Washington 
  

   Zoological 
  Park, 
  and 
  while 
  they 
  are 
  much 
  more 
  persistent 
  than 
  Glossina, 
  they 
  

   clearly 
  " 
  know 
  when 
  they 
  have 
  had 
  enough 
  " 
  and 
  desist 
  from 
  pressing 
  an 
  attack 
  

   on 
  an 
  unwilling 
  host. 
  It 
  is 
  this 
  same 
  trait 
  that 
  is 
  developed 
  to 
  a 
  conspicuous 
  degree 
  

   in 
  Glossina 
  palpalis 
  which 
  explains 
  the 
  great 
  relative 
  immunity 
  of 
  so 
  many 
  animals, 
  

   including 
  probably 
  man 
  and 
  monkey. 
  It 
  is 
  doubtful 
  whether 
  it 
  is 
  nearly 
  so 
  

   strongly 
  developed 
  in 
  Glossina 
  morsitans. 
  

  

  Man. 
  

  

  Life 
  in 
  the 
  fly 
  belt 
  affords 
  a 
  perpetual 
  opportunity 
  to 
  observe 
  and 
  study 
  behaviour 
  

   of 
  fly 
  toward 
  the 
  human 
  host, 
  and 
  the 
  important 
  reactions 
  of 
  the 
  host 
  toward 
  

   the 
  parasite. 
  

  

  The 
  idea 
  that 
  the 
  European 
  is 
  less 
  freely 
  attacked 
  than 
  the 
  native 
  is 
  apparently 
  

   baseless, 
  in 
  so 
  far 
  as 
  the 
  original 
  movement 
  of 
  the 
  insect 
  is 
  concerned. 
  The 
  European 
  

   is 
  more 
  quickly 
  stimulated 
  to 
  retaliatory 
  action 
  — 
  of 
  a 
  purely 
  instinctive 
  and 
  almost 
  

   uncontrollable 
  sort 
  — 
  than 
  some 
  natives, 
  but 
  there 
  is 
  almost 
  or 
  quite 
  as 
  much 
  difference 
  

   between 
  men 
  as 
  between 
  the 
  Indian 
  and 
  Ankole 
  bulls 
  used 
  in 
  the 
  experiment 
  at 
  

   Mbiru. 
  Some 
  of 
  my 
  porters 
  or 
  boys 
  would 
  react 
  to 
  the 
  first 
  approach 
  of 
  a 
  tsetse, 
  

   and 
  these 
  the 
  flies 
  left 
  severely 
  alone, 
  unless 
  there 
  was 
  very 
  great 
  scarcity 
  of 
  other 
  

   food. 
  Others 
  of 
  my 
  canoe-men 
  were, 
  in 
  contrast, 
  extremely 
  apathetic 
  and 
  phleg- 
  

   matic, 
  and 
  would 
  not 
  react 
  to 
  anything 
  short 
  of 
  a 
  severe 
  bite,* 
  and 
  such 
  as 
  these 
  

   were 
  very 
  frequently 
  bitten. 
  Moreover 
  men 
  of 
  phlegmatic 
  temperament 
  would 
  

   calmly 
  compose 
  themselves 
  to 
  sleep 
  squarely 
  in 
  line 
  with 
  the 
  stream 
  of 
  passing 
  

   flies 
  along 
  shore, 
  rather 
  than 
  miss 
  recall 
  to 
  the 
  canoe 
  for 
  foraging 
  expeditions, 
  though 
  

   they 
  might 
  have 
  escaped 
  the 
  fly 
  by 
  going 
  a 
  hundred 
  or 
  two 
  yards 
  inland 
  ; 
  and 
  

   on 
  one 
  occasion 
  something 
  suggestive 
  of 
  the 
  nucleus 
  of 
  a 
  l 
  following 
  swarm 
  ' 
  

   was 
  observed 
  collected 
  upon 
  the 
  sleeping 
  forms 
  of 
  the 
  lazier 
  members 
  of 
  the 
  canoe's 
  

   crew 
  who 
  had 
  thus 
  exposed 
  themselves 
  to 
  attack. 
  

  

  Next 
  to 
  sleeping 
  men, 
  men 
  engaged 
  in 
  an 
  absorbing 
  occupation 
  are 
  most 
  liable 
  

   to 
  attack. 
  I 
  estimate 
  to 
  have 
  been 
  bitten 
  1,500 
  times 
  in 
  18 
  months, 
  and 
  if 
  from 
  

   this 
  total 
  is 
  subtracted 
  such 
  bites 
  as 
  were 
  inflicted 
  in 
  localities 
  when 
  both 
  male 
  

   density 
  and 
  female 
  percentage 
  were 
  high, 
  and 
  when 
  the 
  writing 
  of 
  field 
  notes 
  

   would 
  hardly 
  be 
  undertaken, 
  it 
  is 
  probable 
  that 
  a 
  majority 
  of 
  these 
  bites 
  were 
  

   inflicted 
  while 
  I 
  was 
  note 
  writing. 
  This 
  was 
  my 
  only 
  absorbing 
  occupation 
  in 
  the 
  

   fly 
  belt, 
  but 
  the 
  men 
  had 
  many— 
  repairing 
  canoes 
  ; 
  manufacture 
  and 
  repair 
  of 
  

   fishing 
  tackle 
  ; 
  cleaning 
  of 
  fibre 
  (for 
  lines 
  and 
  cordage), 
  etc. 
  In 
  such 
  cases 
  the 
  

   busiest 
  — 
  not, 
  as 
  above, 
  the 
  laziest 
  — 
  men 
  came 
  in 
  for 
  freest 
  attack. 
  

  

  * 
  The 
  bite 
  of 
  G. 
  palpalis 
  may 
  be 
  absolutely 
  painless, 
  or 
  it 
  may 
  be 
  almost 
  stinglike 
  in 
  

   sharpness, 
  or 
  anywhere 
  between. 
  

  

  